Our knowledge of the galaxy just expanded significantly, thanks to NASA’s Kepler space telescope. The exoplanet-finding machine just discovered 219 new planet candidates – and 10 are roughly the size of Earth and close enough to a star that water might pool on their surface.
This new list of 219 candidate exoplanets is the most comprehensive and detailed from the first four years of Kepler data, according to NASA. It will also be the last catalog from Kepler’s view of a piece of sky in the Cygnus constellation. And it includes a planet National Geographic said could be the most like Earth we’ve found yet: KOI 7711.01.
KOI 7711.01 is only about 30 percent bigger than Earth. It orbits a star 1,700 light-years away that’s quite like our sun, and receives the correct amount of solar warmth necessary for liquid water. Kepler research scientist Susan Thompson of the SETI Institute told National Geographic, “It gets approximately the same amount of heat that we get from our own star.” But there are still a lot of questions surrounding KOI 7711.01. Thompson said, “It’s hard to say whether it’s really an Earth twin – we need to know more about its atmosphere, whether there’s water on the planet.”
After the release this week of the catalog, Kepler has identified 4,034 planet candidates total, according to NASA. 2,335 of those have been verified as exoplanets. The space telescope has also identified around 50 potentially habitable candidates around the size of Earth, with over 30 having been verified.
Thompson said they’re now able to shift the focus away from simply finding new individual systems, and onto learning more about the worlds we think may be like Earth.
This research has also allowed scientists to better classify planets. According to NASA, Kepler data has allowed scientists to discover a division between the sizes of rocky planets around the size of Earth and gaseous planets that are smaller than Neptune. They didn’t find many planets between those two groups. Scientist Benjamin Fulton of the University of Hawaii in Manoa said in a statement, “We like to think of this study as classifying planets in the same way that biologists identify new species of animals. Finding two distinct groups of exoplanets is like discovering mammals and lizards make up distinct branches of a family tree.”